Recurly HPP CSS3 Buttons

Make sure to put type=submit on all buttons if you want them to function in IE

HTML

<button id="pay" type=submit>
    <img src="http://kizer.me/paypal.png" id="paypal">
    Subscribe <span>with</span> Paypal
</button>

<hr>

<button id="pay" class="large" type=submit>
    Subscribe
</button>

<hr>

<button id="pay" class="large" type=submit>
    Subscribe with My Amex
</button>

<hr>

<button id="disabled" type=submit>
    I'm a disabled button
</button>

CSS

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    background-image: url(http://kizer.me/checker.gif);
    margin: 20px 20px;
}

hr {
    margin: 30px 5px;
    border: 0;
    border-top:1px solid #e2e2e2;
}

/* everything above this line is for testing purposes only and not needed in your code base */
/* ======================================================================================== */


button#pay {
    /* === Layout ==== */
    position:relative;
    height: 146px;
    max-width: 600px;
    padding: 0 10px;
    
    /* === Typography ==== */
    font-size: 15px;
    font-weight: 700;
    color: #302106;
    text-shadow: rgba(255,255,255, .5694) 0 1px 0;
    text-align: center;
    
    /* === Style ==== */
    border: 1px solid #767674;
    background: #e7a500;
    
    /* === Round Buttons ==== */
    -moz-border-radius: 10px;
    -webkit-border-radius: 10px;
    border-radius: 10px;
    
    /* === Remove Outlines & Accidential Drags ==== */
    -webkit-user-select: none;
    -moz-user-select: -moz-none;
    cursor: default;
    outline: none;
    
    /* === Button Fill Colors ==== */   
    /* For WebKit (Safari, Google Chrome etc) */
    background-image:-webkit-gradient(linear, 0% 20%, 0% 100%, from(#FECD00), to(#CE7B00));
    /* For Mozilla/Gecko (Firefox etc) */
    background: -moz-linear-gradient(top, #fecd00, #ce7b00);
    /* For Internet Explorer 5.5 - 7 */
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr=#fecd00, endColorstr=#ce7b00);
    /* For Internet Explorer 8 */
    -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#fecd00, endColorstr=#ce7b00)";
    
    /* === Shadows, Inset and Drop ==== */
    /* For WebKit (Safari, Google Chrome etc) */
    -webkit-background-clip: padding-box;
    -webkit-box-shadow:
      rgba(255, 255, 255, 0.699219) 0px 1px 0px inset,
      rgba(0,0,0, 0.269219)...